DE102007029571A1 - Pre-tension setting process for rolling bearing involves regulating temperature of at least one bearing ring - Google Patents

Abstract

The pre-setting tension process is applied to a rolling bearing (3) between two components (1, 2). The inner ring (4) is fitted to one component (1), and the outer ring (5) to the other component (2). The bearing also contains several rolling bodies (6), i.e. balls or rollers. The temperature of at least one of the bearing rings can be regulated independently of that of the other.

Description

The The invention relates to a method for adjusting the bias voltage a rolling bearing, the rolling bearing for the rotatable mounting of a first component in a second component is arranged between the components, wherein the rolling bearing one arranged on the first component bearing inner ring, one on the second Component arranged bearing outer ring and comprises a plurality of rolling elements.

Of Furthermore, the invention relates to a rolling bearing unit with adjustable Preload and a rotary table and a spindle with a corresponding Rolling bearing unit.

A roller bearing generally serves as possible low-friction rotatable mounting of a first component in one second component. To one as possible ensure play-free storage The rolling bearing is usually provided with a bias, d. H. the inner ring of the rolling bearing points opposite the undersize of the first component during the Bearing outer ring across from the second component has an excess.

The Assembly of the bearing takes place in a suitable, from the state of Technique known manner, such. B. by shrinking and / or Press in on or in the corresponding component.

It is therefore already known from the prior art, a rolling bearing with a desired Preload to assemble.

During the Operation of the rolling bearing can but by a change the bias results in problems. If the preload is too low selected can she through through reduces the forces acting on the bearing components of the operation or even be lifted. As a result, the components have a axial and / or radial play on. Is the bias, however chosen too big, comes it during operation of the rolling bearing to overheating of the camp, leading to a further increase in bearing friction and finally to Failure of the camp leads.

Especially problematic and difficult to predict are cases where during operation of the rolling bearing the bearing inner and the bearing outer ring Heat or cool to different temperatures. Depending on the temperature difference between the rings can be both a reduction as also to an increase the bearing preload come. As a result, the bearing points either an undesirable Axial and / or radial clearance or increased bearing friction, which for Failure of the entire machine lead can.

A fluctuating, unpredictable or declining during operation guidance accuracy of rolling bearings especially in machines for positioning or machining of workpieces not tolerable. This concerns among other things so-called round tables, in particular rotary indexing or rotary tables, in general one rotatable in a housing have stored plates. With such rotary tables, for example positioned on the plate arranged workpieces or tools or on the plate clamped workpieces in rotation and supplied to a tool. The elementary component of a rotary table is the roller bearing of the plate in the housing. When bearing clearance occurs, the processing quality deteriorates rapidly, because the plate in the presence of bearing play an undesirable tilting movement run against the horizontal can.

A comparable situation can be found in spindles, where one Spindle shaft is rotatably mounted in a housing. At the end of Spindle shaft is generally a tool (for example, a milling head) fastened. When operating the device now act on the one hand fluctuating and high in terms of amount personnel on the storage of the spindle shaft, on the other hand it comes through Internal (eg bearing friction) or external influences to changing temperature loads of the installed rolling bearing. Also Here it is important to avoid the occurrence of bearing play as well like an excessive increase in bearing friction.

From this it becomes clear that the known method for adjusting the preload a rolling bearing, namely Specify the preload during assembly of the bearing, especially disadvantageous in terms of a consistent guidance accuracy while the operation of the device is. Furthermore, the well-known Method disadvantageous with regard to the effect of changing operating conditions and bearing forces and overall the longevity of the bearing.

Of the The present invention is therefore based on the object, a method to specify the preload of a rolling bearing, the setting the bias depends allowed by the respective operating state.

Of the Invention is also the object of a rolling bearing unit with adjustable preload and a rotary table and a spindle with a corresponding rolling bearing unit specify.

With regard to a method for adjusting the preload of a rolling bearing is the above-mentioned object with the features of the patent claim 1 solved. Thereafter, an initially mentioned method is proposed in which
the temperature of at least one bearing ring is regulated independently of the temperature of the other bearing ring.

According to the invention is recognized been that by means of an independent Control of the temperature of the two bearing rings a change the preload of the rolling bearing balanced or reversed can be. Furthermore, it allows the inventive method when installed, the setting of any bias while the operation of the rolling bearing, so that at any time to changing operating conditions or temperature effects on the rolling bearing can be reacted.

In according to the invention allows the proposed method in particular, on a performance to react, in which the one bearing ring heated or cooled more than the other bearing ring. Such an operating state has always been with a change the preload of the rolling bearing connected, but with the inventive method is compensable. For example, tends to be in the respective rolling bearing unit the bearing outer ring to a stronger one warming as the bearing inner ring, the bearing outer ring can be cooled specifically and vice versa. So remains the previously set or desired bias of the rolling bearing always constant.

With the method according to the invention are neither losses in the guidance accuracy of the rolling bearing another increase the bearing friction by too high a bias to accept.

consequently is the above-indicated object with the proposed method solved.

Even though the invention can be realized by only the temperature of a the two bearing rings is regulated, becomes an embodiment preferably, in which both the temperature of the bearing inner ring than also the temperature of the bearing outer ring independently be regulated by each other. This applies in particular to operating states which both bearing rings heat up, but at different temperatures. In this embodiment the method according to the invention the temperature of both bearing rings can be controlled specifically, so that the preload of the rolling bearing overall remains the same. For temperature measurement on the bearing rings can in all embodiments of the Invention devices according to state serve the art, for example, one or more thermocouples and / or one or more resistance thermometers which are suitable in Way in each adjacent component in indirect or immediate Contact with the bearing ring can be positioned.

Especially preferred is a development in which the temperature of a bearing ring or the temperature of both bearing rings is or will be regulated that the bias during the operation of the rolling bearing remains constant. For temperature monitoring and - adjustment can there - like also in all other embodiments - control devices as per stand the technique can be used, which with the respective preferred cooling or Heating device can correspond in a suitable manner. With The proposed scheme is also possible during operation and when installed Condition of the rolling bearing a to set any bias, namely by selective heating and / or cooling one or both bearing rings.

In a further embodiment of the method according to the invention is the bearing inner ring and / or the bearing outer ring a cooling or heating medium supplied. These may be, for example, water, oil, an emulsion of water and oil, air, or the like. If only a cooling of the provided bearing ring is provided, the use provides of water or air.

Provided a temperature control of both bearing rings is planned, becomes a Training proposed in the bearing inner ring and the Bearing outer ring via separate Supply lines or separate circuits one cooling or heating medium supplied becomes.

Furthermore, the above-mentioned object is achieved with respect to a rolling bearing unit with adjustable bias with the features of claim 6. This claim relates to a
Rolling bearing unit with adjustable preload, with a first component, a second component and an arranged between the components bearings for rotatably supporting the first component in the second component, wherein the rolling bearing arranged on the first component bearing inner ring, arranged on the second component bearing outer ring and a plurality of rolling elements, and wherein the temperature of at least one bearing ring is independent of the temperature of the other bearing ring adjustable.

In accordance with the invention, the proposed rolling bearing unit allows the adjustability of the preload of the bearing both in the installed state and during operation of the entire device. For this purpose, it is provided that the temperature of at least one bearing ring, regardless of the temperature of the other La gerrings is adjustable.

In Reference to advantages, advantageous embodiments and developments the rolling bearing unit according to the invention will be first also on the explanations to the method according to the invention directed.

In A first embodiment of the rolling bearing unit according to the invention are both the temperature of the bearing inner ring as well as the temperature of the bearing outer ring independently adjustable from each other.

in the Generally, a development of the rolling bearing unit is preferred in the bearing inner ring and / or the bearing outer ring a cooling or heating medium supplied is.

in the In view of a particularly accurate and stable control of the ring temperatures may be a rolling bearing unit according to the invention be configured so that the bearing inner ring and the bearing outer ring via separate Supply lines or separate circuits one cooling or heating medium fed is.

To can in the first component one or more channels for feeding and discharging Cooling or heating medium to or from the bearing inner ring and / or in the second component one or several channels for feeding or discharging cooling or heating medium may be formed to or from the bearing outer ring. The Number and diameter of the channels can be under consideration the rolling bearing diameter, the supply or to be supplied heat or the requirement of rapid temperature adjustment.

In particularly preferred manner are in the first and / or in the second component a bearing inner ring or the bearing outer ring at least for the most part surrounding annular channel formed over the respective bearing ring Cooling or Heating medium supplied can be. The annular channel can be a groove-like depression in the component correspond directly limited by the adjacent bearing ring and sealed. So can a complete wetting of the respective Bearing ring with cooling or heating medium and thus a uniform temperature over the entire ring circumference can be adjusted.

alternative or additionally to enable a Heating or cooling by fluid media may with regard to certain applications a rolling bearing unit be provided, in the at least one bearing ring, a cooling device, in particular a chiller or Peltier element, and / or a heating device, in particular a electrical resistance heating, and / or an induction, microwave or radiant heating is assigned.

In In another embodiment, the rolling bearing has a double-row roller bearing on. A double row rolling bearing is characterized by a high load capacity. However, wise the bearing rings of the double row rolling bearing in general a comparatively size Height up, so that the heat dissipation due to the higher Heat capacity conditioned through the larger storage volume difficult. In the rolling bearing unit according to the invention can now when selecting the rolling bearing a consideration the warming tendency of the respective camp except Keep in mind as the bias voltage can be adjusted during operation is.

The roller bearing within the rolling bearing unit can be used as a slant or deep groove ball bearings, as a cylindrical roller bearing, as a needle bearing or be configured. For tilt bearings, the influence of the preload change is due to under different heating of the bearing rings particularly clearly, since these bearings change the radial dimensions results in both a radial and an axial play. The guidance accuracy is therefore particularly inadequate. The proposed rolling bearing unit is therefore particularly advantageous if provided an angular bearing is. Accordingly, the proposed method is also special suitable for adjusting the preload of an angular bearing.

Of Furthermore, the above-indicated object is with regard to a Round table solved with the features of claim 15. With This claim is a rotary indexing or rotary table with a rolling bearing unit according to the invention indicated wherein the first component is a plate and the second component casing having.

at the rotary table according to the invention can the preload of the rolling bearing always be regulated so that neither a radial and / or axial Game of the plate with concomitant machining or positioning inaccuracy occurs, even that increased Bearing friction to fear is. This is a round table for all conceivable operating states, d. H. For all load cases and all conceivable internal and / or external temperature effects specified.

Finally, the above-mentioned object is achieved with respect to a spindle having the features of claim 16. Thereafter, the spindle has a rolling bearing unit according to the invention, wherein the first component has a spindle shaft and the second component has a housing. As a result, a spindle is provided, the greatest possible for all conceivable stress and heat Positioning and machining accuracy associated with a long life.

In Reference to further advantages and developments of the rotary table according to the invention and the spindle according to the invention will also be on the finishes in terms of the method according to the invention and the rolling bearing unit according to the invention directed.

It are now different ways to design the teaching of the present invention in an advantageous manner and further education. This is on the one hand to the subordinate claims, on the other hand to the following explanation a preferred embodiment the method according to the invention and the device according to the invention referring to the drawing. In conjunction with the explanation the preferred embodiments With reference to the drawing are also generally preferred embodiments and further developments of the teaching explained. In the drawing shows the

single Fig. A schematic sectional view of a rolling bearing unit according to the invention, which shown concretely within a rotary table according to the invention is, and by means of which also the inventive method is illustrated.

The only Fig. Shows a schematic sectional view of a rolling bearing unit according to the invention.

A first component 1 is in a second component 2 rotatably mounted, for which a rolling bearing between the components 3 is arranged. The rolling bearing 3 is executed in this rolling bearing unit as a double-row ball bearing. The rolling bearing 3 has one on the first component 1 arranged bearing inner ring 4 and one on the second component 2 arranged bearing outer ring 5 on. Between the bearing rings are a plurality of double row arranged rolling elements 6 ,

In the device shown specifically, the rolling bearing unit shown is part of a rotary table. Therefore, the first component 1 as a plate 7 and the second component 2 as a housing 8th formed.

In accordance with the invention, an independent temperature control of the two bearing rings is made possible by the fact that each bearing ring is assigned its own circuit for supplying and discharging cooling or heating medium. These are both in the first component 1 as well as in the second component 2 channels 9 formed, through which a cooling or heating medium lead to the respective bearing ring and can be derived.

Here are in the plate 7 both a supply line 10 as well as a derivative 11 for the bearing inner ring 4 formed. In this sectional view is in each case only one supply line 10 or derivative 11 Visible, it can be over the circumference of the rotationally symmetric plate 7 however, several such lines may be arranged.

About the supply line 10 can the bearing inner ring 4 a cooling or heating medium are supplied. For this purpose, the supply line opens 10 in a ring channel 12 , Through the inner ring channel 12 can the bearing inner ring 4 be wetted at its entire circumference with cooling or heating medium. The cooling or heating medium can be on the bearing inner ring 4 flow along it until it reaches the inner drainage 11 meets and is returned to the circulation of the cooling or heating medium.

In a further inventive manner are also in the second component 2 that is the case 8th , an external supply line 13 and an external derivative 14 formed, with which the bearing outer ring 5 a cooling or heating medium can be supplied. Also the outer supply line 13 flows into a ring channel 15 , whereby the bearing outer ring 5 completely wettable with the cooling or heating medium.

Instead of a ring channel 12 . 15 distributed over the circumference of the respective component and several wetting points of the cooling or heating medium can be provided with the respective bearing ring. Furthermore, it is possible the ring channels 12 . 15 back into the respective component, so that the bearing ring does not come into direct contact with the annular channel. As a result, an improved bearing seat would be realized, but it would have to be taken into account a deteriorated heat transfer.

With the method according to the invention as well as the devices according to the invention is a completely independent Temperature control of the two bearing rings achieved. So can at any Operating conditions, Loads and heat effects the desired Bearing preload kept constant or any time any Bearing preload can be adjusted.

The temperature monitoring the bearing rings, the temperature of the cooling or heating medium and the regulation of cooling or Heizmediumzufuhr are not shown here, as the expert from known in the art.

In conclusion, be emphasized that the embodiment described above the claimed doctrine discussed but not on the embodiment limits.

Claims (16)

Method for adjusting the preload of a rolling bearing ( 3 ), in particular during operation, wherein the rolling bearing ( 3 ) for the rotatable mounting of a first component ( 1 ) in a second component ( 2 ) between the components ( 1 . 2 ), wherein the rolling bearing ( 3 ) one on the first component ( 1 ) arranged bearing inner ring ( 4 ), one on the second component ( 2 ) arranged bearing outer ring ( 5 ) and a plurality of rolling elements ( 6 ), and wherein the temperature of at least one bearing ring ( 4 . 5 ) regardless of the temperature of the other bearing ring ( 4 . 5 ) is regulated. A method according to claim 1, characterized in that both the temperature of the bearing inner ring ( 4 ) as well as the temperature of the bearing outer ring ( 5 ) are regulated independently of each other. Method according to claim 1 or 2, characterized in that the temperature of a bearing ring ( 4 . 5 ) or the temperature of both bearing rings ( 4 . 5 ) is regulated so that the bias voltage during operation of the rolling bearing ( 3 ) remains constant. Method according to one of claims 1 to 3, characterized in that the bearing inner ring ( 4 ) and / or the bearing outer ring ( 5 ) is supplied to a cooling or heating medium. Method according to one of claims 1 to 4, characterized in that the bearing inner ring ( 4 ) and the bearing outer ring ( 5 ) via separate supply lines ( 10 . 13 ) or separate circuits each a cooling or heating medium is supplied. Rolling bearing unit with adjustable preload, with a first component ( 1 ), a second component ( 2 ) and one between the components ( 1 . 2 ) arranged rolling bearings ( 3 ) for rotatably supporting the first component ( 1 ) in the second component ( 2 ), the rolling bearing ( 3 ) one on the first component ( 1 ) arranged bearing inner ring ( 4 ), one on the second component ( 2 ) arranged bearing outer ring ( 5 ) and a plurality of rolling elements ( 6 ), and wherein the temperature to at least one bearing ring ( 4 . 5 ) regardless of the temperature of the other bearing ring ( 4 . 5 ) is controllable. Rolling bearing unit according to claim 6, characterized in that both the temperature of the bearing inner ring ( 4 ) as well as the temperature of the bearing outer ring ( 5 ) are independently controllable. Rolling bearing unit according to claim 6 or 7, characterized in that the bearing inner ring ( 4 ) and / or the bearing outer ring ( 5 ) is a cooling or heating medium can be fed. Rolling bearing unit according to one of claims 6 to 8, characterized in that the bearing inner ring ( 4 ) and the bearing outer ring ( 5 ) via separate supply lines ( 10 . 13 ) or separate circuits each a cooling or heating medium can be fed. Rolling bearing unit according to one of claims 6 to 9, characterized in that in the first component ( 1 ) one or more channels ( 9 ) for the supply and discharge of cooling or heating medium to or from the bearing inner ring ( 4 ) and / or in the second component ( 2 ) one or more channels ( 9 ) for the supply and discharge of cooling or heating medium to or from the bearing outer ring ( 5 ) are formed. Rolling bearing unit according to claim 10, characterized in that in the first and / or in the second component ( 1 . 2 ) a bearing inner ring ( 4 ) or the bearing outer ring ( 5 ) at least for the most part surrounding annular channel ( 12 . 15 ) is formed. Rolling bearing unit according to one of claims 6 to 11, characterized in that at least one bearing ring ( 4 . 5 ) is assigned a cooling device, in particular a refrigerator or a Peltier element, and / or a heating device, in particular an electrical resistance heater, and / or an induction, microwave or radiant heater. Rolling bearing unit according to one of claims 6 to 12, characterized in that the rolling bearing ( 3 ) has a double row rolling bearing. Rolling bearing unit according to one of claims 6 to 13, characterized in that the rolling bearing ( 3 ) is configured as an angular or deep groove ball bearing, as a cylindrical roller bearing or as a needle bearing. Rotary table, in particular rotary indexing or rotary table, with a roller bearing unit according to one of claims 6 to 14, wherein the first component is a plate ( 7 ) and the second component a housing ( 8th ) having. Spindle with a rolling bearing unit according to one of claims 6 to 14, wherein the first component is a spindle shaft and the second Component housing having.